PARTULA CLARA. AS 
Smith, Annotated List, 1902), he wrote: “P. clara is not a Moorea species. It is a 
very rare local Tahiti species and, like annectens and turgida, appears to be gradually 
becoming extinct. JI have only three examples in my collection.”' In view of these 
specific statements, based upon Garrett’s painstaking and detailed study of all 
parts of Tahiti, as evidenced by his circumstantial account of the snail populations 
of various valleys designated by name, there can be no doubt that this species was 
actually very rare in his time and in great danger of becoming extinct. 
Mayer, in 1899, obtained 61 snails from Vaihiria Valley, an important element 
of the range of clara. Apparently 5 light dextral shells and 1 dark dextral shell 
among these were clara, although Mayer regarded them as dextral varieties of sinis- 
trorsa, a form of otaheitana. In my own collections, 619 adult and adolescent snails 
were taken in Vaihiria, and none of them is a dextral otaheitana; hence | judge that 
Mayer’s dextral shells were clara. ‘The further point of interest is that Mayer’s 
dextral snails amounted to about to per cent of his whole collection in this valley. 
Of my adult snails, 23.23 per cent from this locality belong to the species under 
consideration. It is certain, therefore, that a great.increase in relative numbers 
has come about in a very few years. 
Finally, in this connection, we may note the figures denoting the relative fre- 
quency of P. clara in the island as a whole. The yield of 43 valleys amounted to 
819 adult clara individuals, and of these valleys the general populations numbered 
16,005 adults; thus clara forms 5.1 per cent of the total population in the valleys 
definitely inhabited. But the whole range of this species includes 52 valleys, for 
9 valleys in the inhabited quadrants or major regions did not disclose clara among 
their inhabitants. The total adult population of these 52 valleys was 18,015, and 
the 819 snails of the present species amount to 4.5 per cent of this figure. Lastly, 
of the 24,085 adults representing the inhabitants of the whole island, the 819 P. clara 
constitute 3.4 per cent. According to the point of view, therefore, this species 
forms 5.1 per cent, 4.5 per cent, or 3.4 per cent of the population. In brief, then, 
in 1879 only 3 specimens of clara were in Garrett’s hands; in 1899 Mayer obtained a 
collection from Vaihiria, of which ro per cent were clara, while from the same valleys, 
from 1906 to 1909 inclusive, I obtained 23.13 per cent of this species; clara forms 
5.1 per cent or 4.5 per cent of the snail fauna of its range and 3.4 per cent of the 
whole population. It is obvious that it has materially increased in numbers during 
recent years. 
Il. Formerly greatly restricted in its habitat, Partula clara now ranges over about 
four-fifths of the entire island of Tahiti. From Garrett’s rough chart, published by 
Hartmann, given in its original and in its corrected form in text-figures 2 and 3, the 
_ area inhabited in his time extended from about Tereehiato Tenaire or Titaviri Valleys. 
It has been shown that now this range is increased so as to include the western sector 
as far northward as Punaruu, all of Taiarapu, and all of the eastern quadrant to and 
including Papenoo Valley. It is certain that these newly-won localities were not 
peopled by clara in Garrett’s time. For instance, he correctly describes the forms of 
1The italics of the last sentence are of the present author. 
